The directors of 'John Wick', Chad Stahelski and David Leitch just confirmed to Movies.com that 'John Wick 2' is in development. They are brainstorming ideas for the film but haven't started writing the script. In an interview, he told the site:

If there’s great action but you have a character that no one likes and doesn’t have charisma, you’re not going to watch it. Look at any great action star, whether it’s Harrison Ford or Liam Neeson or Robert Downey Jr., pick a name. You love the guy first. Good action, bad action, you just love them in action. So we want to make sure we have a story and a character that everybody loves and then we’ll dress it with action that we promise will be awesome.

— Movies.com

If you have read our review of 'John Wick', you would know that we really enjoyed the movie. It has given life to the popcorn action movie genre. The movie was full of intense fights, Keanu Reeves was great and overall, it was a very solid movie. It concentrated on the topic of an ex-hitman that is losing his skills and not at his prime anymore.

I genuinely hope that the directors do not pull a 'Hangover' and do the same thing again in a sequel. It would be much more interesting to explore the character's past (when he was at his prime) or his future where he gets back in the business, rather than him going on a revenge-spree one more time.

In general, this movie has high potential and a universe that has a lot left to be explored. The first 'John Wick' made 78 million dollars with a budget of 20 million, and there is no doubt that those numbers will increase for the sequel.